In various applications there is a need for accurate, repeatable and reliable measurement of linear and/or rotary motion and position. For example, magnetic sensors can be used for such linear and/or rotary motion and position sensing. For this purpose, one or more permanent magnets may be attached to a target, and the magnetic field resulting from the one or more permanent magnets may be measured by one or more magnetic sensors.
Some magnetic position sensor make use of so-called multi-pole magnet(ic) strips. A multi-pole magnet strip provides alternating north and south poles across the length of the strip. A resulting alternating magnetic field across the length of the strip may enable a sensor to read and identify its position along the magnetic strip. For example, multi-pole permanent magnetic encoders may be used for wheel speed sensing in automotive systems.
Conventional solutions for position sensing using magnetic sensors suffer from drawbacks, however. Some solutions do not have the capability to sense position in multiple dimensions. Others are not accurate and/or require mathematically complex calculations that are difficult to carry out with limited silicon area.
Therefore, there is a need for roved magnetic position sensors, sensing systems and methods.